《植物生理学报》 2016, 52(8): 1255-1262

珙桐MYB转录因子DiMYB1基因的克隆及表达分析

戴鹏辉^*, 任锐^*, 曹福祥, 刘志明, 李萌^**

中南林业科技大学生命科学与技术学院, 长沙410004

通信作者：戴鹏辉；E-mail: limeng0422@foxmail.com

摘　要：

根据珙桐转录组测序结果, 筛选到一个与原花青素合成相关的基因, 通过克隆该基因片段并进行序列分析确定该基因编码一个珙桐MYB转录因子, 将其命名为DiMYB1 (GenBank登录号KR996175)。该基因开放阅读框全长为924 bp, 编码产物包含307个氨基酸。对其编码产物的基本理化性质、亲水性和疏水性、保守结构域、亚细胞定位等方面进行了生物信息学分析和预测。对DiMYB1基因编码产物的氨基酸序列进行聚类分析表明, 其与拟南芥MYB123转录因子的同源性最高。应用qRT-PCR分析该基因的表达模式发现, DiMYB1基因在珙桐紫色幼叶中的表达量最高, 其次是雄蕊, 在芽、茎、成熟叶片、苞片、果肉和种子中只有微量表达。另外, DiMYB1基因的表达量在珙桐败育种子中显著高于正常种子, 且在中期败育种子中表达量达到最高。构建原核表达载体pET-28a (+)-DiMYB1, 并在大肠杆菌BL21 (DE3)中获得高效表达。本研究通过对DiMYB1基因进行克隆与表达分析, 为探索该基因在珙桐逆境胁迫、花青素合成和种子发育过程中的调控功能奠定基础。

关键词：MYB转录因子; 原花青素合成; 逆境胁迫; 珙桐

收稿：2016-05-23   修定：2016-07-18

资助：湖南省百人计划(112-0991)、中南林业科技大学博士科研 基金(0490016)和中南林业科技大学青年基金(QJ201512)。 * 并列第一作者。

Cloning and expression analysis of a gene encoding MYB1 transcription factor in Davidia involucrata

DAI Peng-Hui^*, REN Rui^*, CAO Fu-Xiang, LIU Zhi-Ming, LI Meng^**

College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China

Corresponding author: DAI Peng-Hui; E-mail: limeng0422@foxmail.com

Abstract:

According to the Davidia involucrata transcriptome sequencing data, a gene involved in proanthocyanin biosynthesis was selected. The target gene was identified to encode a MYB1 transcription factor in D. involucrate by cloning and sequence analysis and named as DiMYB1 (GenBank accesssion No. KR996175). The fragment of DiMYB1 includes a ORF (open reading frame) of 924 bp, which encodes a protein product of 307 amino acids. Bioinformatic analysis and prediction have been conducted to identify the physicochemical property, hydrophilia and hydrophobicity, conserved domain and subcellular localization of DiMYB1 protein. Phylogenetic analysis based on the amino acid sequence of DiMYB1 indicated it has the highest homology with Arabidopsis thaliana MYB123 transcription factor. Expreesion patterns of DiMYB1 was detected by qRT-PCR and the result showed that DiMYB1 had the highest transcript abundance in purple young leaves, followed by purple stamens, while had the less transcript abundance in buds, stems, mature leaves, bracts, fruits, and seeds. In addition, transcript abundance of DiMYB1 in abortive seeds was significantly higher than in normal seeds, and reached the peak in the middle developmental stages in abortive seeds. Subsequently, prokaryotic expression vector of pET-28a (+)-DiMYB1 has been constructed successfully and was induced to express effectively in E. coli BL21 (DE3). This work lays a foundation for further exploring the function of MYB1 transcription factors in response to stress, proanthocyanin biosynthesis and development regulation in D. involucrata.

Key words: MYB1 transcription factor; proanthocyanin synthesis; stress conditions; dove tree (Davidia involucrata)